1. Field of the Invention
This invention relates to a high speed image pick-up apparatus arranged to be capable of producing a video signal having a high degree of information density in the direction of the time base of the signal.
2. Description of the Related Art
For the high speed image sensing system of a video camera, it has been known to raise both a vertical scanning frequency fVS and a horizontal scanning frequency fHS at the same rate. However, a method of simply raising these scanning frequencies fVS and fHS necessitates an increase in the frequency band of the signal processing circuit of the camera as the signal frequency likewise becomes higher. Further, in cases where a video signal produced from the camera is to be recorded, such a simple method also necessitates the use of a recording device which has a wide frequency band and is, therefore, very expensive. In the case of a TV signal of the NTSC system, for example, the video signal frequency band is approximately from 0 to 4 MHz. If the processing speed for this signal is to be increased by five times, the camera and the recording device must be arranged to be capable of processing a signal of a frequency band from 0 to 20 MHz.
In accordance with a conceivable method for permitting a recording operation within a lower signal frequency band, the video signal may be divided into a plurality of recording channels. However, the dividing method results in a complex recording signal processing arrangement. Besides, reproduction of the signal recorded in such a manner also requires a complex signal processing arrangement. Therefore, it necessitates use of expensive recording and reproducing systems.
Further, with the signal frequency increased as a whole, in cases where the video signal output of the system is to be displayed by a monitor device, the monitor inevitably becomes expensive as it must be arranged to be capable of operating at a higher speed in response to the increased signal frequency.
Meanwhile, in the field of the home video cameras, video cameras having a high shutter speed of 1/1000 or 1/2000 sec or thereabout have been commercialized. As a result of this, there has arisen a public desire for a video camera and a video recording and/or reproducing system which are capable of producing a video signal having high information density in the direction of time base and yet are inexpensive.